The present invention relates to a force sensor for sensing forces, such as the draft forces applied to the implement hitch of an agricultural tractor.
To provide draft control for agricultural tractors a means of measuring the draft force is required. Known draft force measuring mechanisms for tractor draft control systems are described in U.S. Pat. No. 4,059,159, issued in 1977 to Moorhouse et al, in U.S. Pat. No. 3,342,274, issued in 1967 to Wridt, Jr. and in U.S. Pat. No. 3,375,876, issued in 1968 to Engelmann. In these known designs the draft forces are applied to laterally spaced apart spring members and the deflection of the spring members is measured to provide a signal indicative of the draft force. However, none of these designs is practicable for use in certain production articulated agricultural tractors wherein the draft links have front ends which are coupled to structural beams which extend between and are rigidly attached to front and rear drawbar supports. Accordingly, a relatively simple, inexpensive and sensitive draft force sensing mechanism is desired for use in such production articulated agricultural tractors.